Interactive television (iTV) is currently available in varying forms, each of which combines, in some form or other, the passive viewing experience of traditional TV viewing with the interactive nature of the World Wide Web. Thus, in different implementations, iTV might allow viewers (or subscribers) to review local news headlines or weather forecasts while watching their favorite television shows and/or electronically chatting with other viewers about the latest plot twists. Such text and graphics information is referred to as Managed Content. Certainly all iTV systems have a version of an interactive program guide or electronic program guide (IPG or EPG, respectively) that allows subscribers to learn about and select desired programming
Such programming generally comes in two forms: linear and non-linear. Linear programming is another name for traditional broadcast programming That is, programming that is available for viewing by subscribers according to a schedule promulgated by the iTV service and/or content provider. Current IPGs allow subscribers to browse and select linear programming and some also include the ability to subset linear program listing data by subject or type of programming.
In addition to linear or broadcast television, subscribers may now also be given opportunities to select from a list of programs that are not linear, but instead are provided on-demand. Such content is generically referred to as non-linear programming or Video on Demand (VOD). Current IPGs for browsing and selecting VOD programs include the ability to select such programming from categories of non-linear (on-demand) programming.